Internal gear pump



y 4, 1950 E. s. WETCHGER 2,513,984

INTERNAL GEAR PUMP Filed Nov. 21, 1947 2 Sheets-Sheet 1 1N! 'EN TOR. [UGAVYE J Min/65 3 -4 v A rromvzr:

Patented July 4, 1950 INTERNAL GEAR PUMP Eugene S. Witchger, Grosse Pointe Woods, Mich., anignor to Eaton Manufacturing Company, Cleveland, Ohio, a corporation of Ohio Application November 21, 1947, Serial No. 787,386 Claims. (Cl. 103-126) This invention relates to fluid pumps and more particularly to novel structural details of internal gear pumps.

Broadly the invention comprehends the provision of a pump of the internal gear type comprising inner and outer eccentrically associated intermeshing rotors arranged in a unitary housing and end cover plate structure, said cover plate serving the dual purpose as a cover for shipping the pump as an assembled unit and as an intake and discharge port plate in the proper assembly of the pump for operative use.

An object of the invention is the provision of a pump structure of the internal gear type that can be shipped as a unit and which is directly mountable upon driving mechanism therefor in intake and discharge port relation.

Another object of the invention is the provision of an internal gear pump comprising a pair of intermeshing rotors arranged in a pump housing having accurate porting therein and having a thin cover plate thereon enclosing the pump rotors in the housing, said plate being so ported so as not to materially weaken the plate and yet prevent pump pinching at the end of the ported cycle.

A further object of the invention is the provision of an internal gear pump provided with a thin end cover plate for enclosing the pump/gears and providing novel multiple aperture intake and discharge porting.

Other objects and advantages of the invention will appear from the following description taken in connection with the drawings, forming a part of the specification; and in which: v

Fig. 1 is a fragmentary end plan view of an internal gear pump, constituting the invention from the cover plate end thereof;

Fig. 2 is a vertical cross-sectional view of the pump of Fig. 1;

Fig. 3 is an end plan view of the pump rotors taken along line 3-3 of Fig. 2; and

Fig. 4 is an end plan view of the accurate porting in the pump housing taken along line 4-4 of Fi 2.

The present invention is directed at the provision of an internal gear pump as a serviceable pump unit adapted to be mounted as part of an internal combustion engine, engine transmission or the like preferably utilizing a shaft thereof as the driving means therefor. As a means of providing an eflicient, economical pump structure of this sort a structural unit is provided comprising a pair of inner and outer intermeshing gear rotors arranged for eccentric motion 2 relative to one another within a pump housing having accurate porting therein for the pump and having secured on the face thereof enclosing the rotors a thin cover plate having porting therein adapted to communicate with appropriate fluid supply and discharge channels of mechanism to be associated therewith. The cover plate serves to make a unitary enclosed pump structure that can be easily handled for shipping and which upon attaining its destination can be immediately assembled relative to the transmission housing or the like with which it is to be associated without the necessity of addition or removal of structure relative thereto. The intake and discharge porting in the plate although it need not be accurate because of the provision of accurate porting in the housing consists of a plurality of predetermined spaced apertures extending throughout the proper cycle of intake and discharge accurate porting. By the provision of this kind of porting, the plate in view of its thin construction, to reduce weight and minimize space requirements, is not unduly weakened and yet prevents pinching at the ends of the ported cycle to relieve any fluid trapping effect that might otherwise occur in the pump. Furthermore, by extending the porting as above described, the noise level of the pump iii operation is not increased.

Referring to th drawings for more specific details of the inve tion, It represents generally an internal gear pump comprising a pump housing l2, a pair of intermeshing gear rotors l4 and I6 and an end cover plate IS.

The rotor 14 is mounted for rotation in a chamber 2|! of the pump housing l2 upon a circumferential wall 22 thereof and has a plurality of internal lobes or gear teeth 24 adapted to mesh with the external lobes or gear teeth 26 of rotor l6, said rotor It being suitably splined for rotation eccentric to rotor l4 upon a shaft 28. In View of the intended adaptability of the pump structure in supported relation upon mechanism with which it is to be associated, the shaft 28 is preferably a part of said mechanism.

Accurate intake and discharge porting 38 and 32 respectively is provided in the housing l2 oppositely disposed from the cover l8 relative to the rotors l4 and i6.

The plate l8 which is suitably secured upon the housing I2 in the initial assembly of the pump as a unitary structure and remains as an integral part of the pump in the operative use thereof provides a series of apertures 34, 36, and 38 respectively constituting the intake port for the pump and another of apertures 40, 42, and 44 reatlases spectively constituting the discharge port for the pump, said series of intake and discharge ports being adapted to be placed in proper fluid communication with intake and discharge channels provided in the mechanism upon which the pump is to be mounted.

The series apertures 84,18, and 88, and 49, 42, and 44 extend throughout the ported cycle of the accurate porting provided in the housing 12 and, as such, permit a. major flow-region in the area 01' apertures 36 and 42 and prevent any pinch at the ends thereof to thereby relieve any trapping effect that might otherwise occur if this provision were not made. series of apertures instead of a single portextending throughout the ported cycle of the necessary accurate porting a like result is attained without materially weakening the plate 18.

With the arrangement of the accurate porting in the pump housing and the provision of an end cover plate of thin construction having porting therein extending throughout the angular range of the accurate porting, such that the plate remains amply sturdy for use as a component part of the pump both for handling and operation, a pump structure is provided that is adaptable to a wide range of uses in its adaptations to engines, transmissions and the like.

While this invention has been described in connection with certain specific embodiments, the principle involved is susceptible of numerous other applications that will readily occur to persons skilled in the art. The invention, there- .fore, is limited only as indicated by the scope of the appended claims.

What I claim is:

1. A rotor pump comprising a housing having a chamber and accurate intake and discharge porting arranged therein in communication with the chamber, pumping means in said chamber comprising inner and outer eccentrically related rotors having interengaging teeth, and a cover plate on the housing enclosing the rotors within the chamber having multiple apertured intake and discharge porting each having its apertures as a group extending arcuately in spaced array substantially equal in arcuate extent to the respective accurate intake and discharge porting in the housing. v

2. A rotor pump comprising a housing having a chamber and accurate intake and discharge porting communicating with the chamber, a pair of inner and outer eccentrically related rotors rotatably mounted in the chamber, a drive means for the inner rotor, an end cover plate, on the housing enclosing the rotors within the housing,

having two sets of a plurality of varied size apertures therein predeterminedly spaced and constituting intake and discharge porting {or the pump oppositely disposed to the accurate porting in the housing.

3. A pump adapted to be juxtaposedly arranged upon associated mechanism having suit-' able fluid supply and discharge channels therein for the pump comprising a housing having a chamber therein open at one end and having accurate intake and discharge passages in the other end communicating with the chamber, a pair of interengaging inner and outer rotors By so providing a in the chamber, and an end plate on the housing closing oil. the chamber and enclosing the rotors therein, said plate having intake and discharge porting each comprising a plurality of arcuately arranged and spaced apertures extending substantially throughout the cycle of the intake and discharge passages in the housing and adapted to lie adjacent the respective pump fluid supp and discharge channels in the associated mechanism.

4. A pump comprising a housing having an internal peripheral wall and end wall defining a chamber and arcuate extending accurate pumping intake and discharge passages in the end wall thereof, a pair of inner and outer intermeshing rotors in the chamber with the outer rotor in bearing relation in the peripheral wall of the housing and an end plate mounted upon the housing enclosing the rotors within the chamber having a set of apertures predeterminedly spaced from one another extended over an arcuate range substantially coinciding with the arcuate extent of the intake passage inthe housing constituting an intake passage means and another set of apertures predeterminedly spaced from one another extended over an arcuate range substantially coinciding with the arcuate extent of the discharge passage in the housing constituting a discharge passage means.

5. A pump adapted to be assembled for use upon operating mechanism having fluid intake and discharge passages therein for'the pump,

said pump being associated with said operating mechanism in'juxtaposed fluid intake and discharge relation and comprising a pump housing having a shallow bore and respective accurate intake and discharge passages communicating with the bore, a pair of inner and outer eccentrically related rotors having interengaging teeth rotatably mounted in the bore, and a relatively thin cover member secured to the housing enclosing the rotors in the bore having a'plurality of angularly spaced apertures communicating with the bore arranged oppositely disposed from the intake passages in the housing and another plurality of angularly spaced apertures communicating with the bore arranged oppositely disposed from the discharge passage in the housing, said flrst and second mentioned sets of apertures adapted to cooperate respectively with the pump fluid intake and discharge passages in the operating mechanism with which the pump is to be associated with one of the apertures of each set of apertures providing a major flow area for the respective fluid intake and discharge passages provided thereby.

- EUGENE S. WITCHGER.

REFERENCES CITED The following references are of record in the flle of this patent:

UNITED STATES PATENTS Witchger Oct. 1, 1946 

